Resection of a giant primary synovial sarcoma of the inferior vena cava extending into the right atrium with caval reconstruction under cardiopulmonary bypass and circulatory arrest

Background. Synovial sarcoma primarily arises in para-articular locations of the extremities. However, numerous unique sites of origin have been reported. There are only 5 known cases of primary intravascular synovial sarcoma. Methods. We present the second reported case of synovial sarcoma arising from the inferior vena cava (IVC) in a 41-year-old woman with progressive fatigue, abdominal distension, and lower-extremity swelling. This is the first known case with a monophasic histological subtype. Results. The tumor arose from the retrohepatic IVC with cephalad extension into the right atrium. Excision required cardiopulmonary bypass and deep hypothermic circulatory arrest, followed by bovine pericardial patch reconstruction of the IVC. Conclusions. Primary synovial sarcoma of the IVC is rare. The use of cardiopulmonary bypass with or without deep hypothermic circulatory arrest may be required if there is tumor extension into the heart. Bovine pericardium is an excellent material for caval reconstruction.